US-12620616-B2 - Electrode assembly for secondary battery and method of manufacturing same

US12620616B2US 12620616 B2US12620616 B2US 12620616B2US-12620616-B2

Abstract

Proposed is an electrode assembly for a secondary battery, the electrode assembly includes a stacked body including a first electrode plate, a second electrode plate, and a separator interposed between the first electrode plate and the second electrode plate, and an outer periphery of the stacked body may be wound with the separator for exterior finishing. In addition, the present disclosure may include a method of manufacturing an electrode assembly for a secondary battery that is externally finished with a separator.

Inventors

JI WON YANG
Young Rae OH
Jae Young Jung

Assignees

SK ON CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20221230
Priority Date: 20211231

Claims (13)

1 . An electrode assembly for a secondary battery, the electrode assembly comprising a stacked body comprising: a first electrode plate; a second electrode plate; and a separator interposed between the first electrode plate and the second electrode plate, wherein the separator includes a folding part folded to allow the first electrode plate and the second electrode plate to be alternately stacked and a winding part continuously extending from an end of the folding part, and wherein the winding part winds an outer surface of the stacked body and is extended in length such that a winding end is positioned on a vertical surface facing a width direction orthogonal to a stacking direction of the stacked body, and is exterior-finished.
2 . The electrode assembly of claim 1 , wherein the bonding region of the separator is formed on the vertical surface of the stacked body.
3 . The electrode assembly of claim 1 , wherein the folding part is folded in a zigzag shape.
4 . The electrode assembly of claim 1 , wherein the winding end covers more than ½ of the height of the vertical surface in the stacking direction.
5 . The electrode assembly of claim 1 , wherein the winding end of the separator is bonded with a bonding member disposed on an outer surface of the winding part that winds the outer periphery of the stacked body.
6 . The electrode assembly of claim 1 , wherein the winding end of the separator comprises irregularities having a depth ranging from 0 mm to 2 mm on a cut surface.
7 . The electrode assembly of claim 5 , wherein the bonding member comprises an adhesive.
8 . A method of manufacturing an electrode assembly for a secondary battery, the method comprising: forming a stacked body in which first electrode plates and second electrode plates are alternately stacked between a folded separator; cutting the separator to have an extended length capable of winding around an outer periphery of the stacked body; winding an outer periphery of the stacked body with the separator; applying a bonding member on the outer surface of the stacked body; and bonding the separator to a bonding member applied to an outer surface of the stacked body; wherein the separator is formed to include a folding part folded to allow the first electrode plate and the second electrode plate to be alternately stacked and a winding part continuously extending from an end of the folding part, and wherein the winding part winds the outer surface of the stacked body and is extended in length such that a winding end is positioned on a vertical surface facing a width direction orthogonal to a stacking direction of the stacked body while winding the outer surface of the stacked body.
9 . The method of claim 8 , wherein in applying the bonding member, the bonding member is applied on the vertical surface of the stacked body.
10 . The method of claim 8 , wherein in bonding the separator, the winding end of the separator is pressed against and brought in close contact with the vertical surface of the stacked body.
11 . The method of claim 8 , wherein the method further comprises providing a tension to the separator before cutting the separator.
12 . The method of claim 8 , wherein the method further comprises preheating a preset cutting line portion of the separator.
13 . The method of claim 8 , wherein the winding end of the separator comprises irregularities having a depth ranging from 0 mm to 2 mm on a cut surface.

Description

The present application claims priority to Korean Patent Application No. 10-2021-0193916, filed Dec. 31, 2021, and KR Patent Application No. 10-2022-0169135, filed Dec. 6, 2022, each of which is incorporated herein for all purposes by this reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to an electrode assembly for a secondary battery. More particularly, the present disclosure relates to an electrode assembly that is wound with a separator to finish the exterior. 2. Description of the Related Art Secondary batteries can be repeatedly charged and discharged and can be applied to various fields such as mobile devices, electric vehicles (EVs), hybrid vehicles (HEVs), energy storage systems (ESSs), and the like. In regard to such secondary batteries, products that can output more compact and stronger power have been developed. Typically, a secondary battery is composed of an electrode assembly and an exterior pouch material for encasing the electrode assembly and an electrolyte, in which the electrode assembly is composed of a cathode plate, an anode plate, and a separator. An insulating tape is attached to the outer peripheral surface of an electrode assembly that is a rolled stack of a cathode plate, an anode plate, and a separator to maintain the rolled and stacked state of the electrode assembly. As disclosed in Patent Document 1, in the case of the conventional electrode assembly, an insulating tape is attached to the stacked surface of a stacked body of a cathode plate, an anode plate, and a separator. The ends of the insulating tape wound around the electrode assembly overlap on the outer peripheral surface of the electrode assembly, the thickness of the electrode assembly in the direction of stacking inevitably increases. As known to those skilled in the art, the thickness of secondary batteries has been gradually reduced in order to increase energy density, that is, volume energy density (energy per unit volume of battery). However, the electrode assembly, which is finished with a taping method as in Patent Document 1, has a result that goes against the trend of reducing the thickness of a secondary battery. Documents of the Related Art Patent Document (Patent Document 1) Korean Patent No. 10-2183796 SUMMARY OF THE INVENTION The present disclosure has been created to solve the above-described problems, and an objective of the present disclosure is to provide an electrode assembly in Which an exterior surface of a stack thereof is finished with a separator. In addition, the present disclosure includes an electrode assembly manufacturing method by which the exterior of the electrode assembly is finished by winding an unfolded winding part of a separator. In order to achieve the above objective, an electrode assembly for a secondary battery according to the present disclosure includes a stacked body including: a first electrode plate; a second electrode plate; and a separator interposed between the first electrode plate and the second electrode plate, in which an outer periphery of the stacked body is wound with the separator for exterior finishing. Preferably, a bonding region of the separator may be positioned on a vertical surface orthogonal to a stacking direction of the stacked body. In an embodiment of the present disclosure, the separator includes a folding part folded to allow the first electrode plate and the second electrode plate to be alternately stacked and a winding part continuously extending from an end of the folding part. The winding part may wind the outer surface of the stacked body and may be extended in length so as to position a winding end on a vertical surface orthogonal to the stacking direction of the stacked body. In addition, the folding part may be folded in a zigzag shape. Alternatively, the winding end may cover more than ½ of the height of vertical surface orthogonal to the stacking direction. In addition, according to the present disclosure, the winding end of the separator may be bonded with a bonding member disposed on an outer surface of the winding part that winds the outer periphery of the stacked body. In the present disclosure, the winding end of the separator may have irregularities having a is depth ranging from 0 mm to 2 mm on a cut surface. Furthermore, the bonding member may include an adhesive. A method of manufacturing an electrode assembly for a secondary battery according to the present disclosure includes: forming a stacked body in which a first electrode plate and a second electrode plate are alternately stacked between a folded separator; cutting the separator to have an extended length capable of winding around an outer periphery of the stacked body; winding an outer periphery of the stacked body with the separator; applying a bonding member on the outer surface of the stacked body; and bonding the separator to a bonding member applied to an outer surface of the stacked body. In an embodiment of the prese